According to a Wikipedia article on Saki which references an essay by Dominic Hibberd in the Oxford Dictionary of National Biography:

Saki was a Tory and somewhat reactionary in his views.

This information is helpful in understanding his story "Dusk" and his characterization of Norman Gortsby. Norman is a young man and has a lot to learn about human nature and reality. He is quite an observer of humanity but has not yet digested what he has observed. Saki uses this young, naive viewpoint character to dramatize his thesis, which has a "Tory" and a "somewhat reactionary" foundation. Gortsby's sentiments about suffering humanity change from indifference to sympathy and back to indifference, if not antipathy--all as a result of his experience in the gathering darkness.

When the story opens, Gortsby is observing the

Men and women, who had fought and lost, who hid their fallen fortunes and dead hopes as far as possible from the scrutiny of the curious. . .

He had failed in a more subtle ambition, and for the moment he was heartsore and disillusioned, and not disinclined to take a certain cynical pleasure in observinig and labelling his fellow wanderers as they went their ways in the dark stretches between the lamp-lights.

"Not disinclined" seems like a double negative. He was inclined to take a cynical pleausre in observing the "men and women, who had fought and lost." Gortsby is a bit of a Tory and reactionary himself. He sees life as a struggle, bellum omnium contra omnes, "the war of all against all." He is a poor choice for the young con man who sits down and begins to tell him a hard-luck story about losing his hotel and needing to borrow money to rent a room for the night.

Gortsby listens tpatiently, and then:

"Of course," said Gortsby slowly, "the weak point of your story is that you can't produce the soap."

Gortsby does not say that he would have given the other man any money if he had been able to produce a cake of soap from the chemist's. But when he discovers the cake of soap on the ground and naturally assumes it belonged to the other man, he feels ashamed of his cold-hearted attitude towards his fellow man. No doubt he is experiencing mingled emotions of guilt, shame, and remorse as he races after the stranger and gives him a sovereign and the expensive soap. As he returns in the direction of the bench where they had been sitting, he tells himself:

"It's a lesson to me not to be too clever in judging by circumstances."

He is becoming less of a Tory and more of a Liberal. But then he discovers that the cake of soap he found actually belonged to the elderly getleman who had been sitting beside him earlier, and he realizes that he was a sucker for trusting the young man to repay the sovereign. He must also realize that the elderly gentleman might  be another con man telling the same story to suckers but having the foresight to procure a cake of soap which he left near the bench intending to come back and use it as a gambit to start a conversation with Gortsby.

Now Gortsby realizes that you can't trust anybody. It really is a struggle for survival of the fittest, a war of all against all, bellum omnium contra omnes. Gortsby will harden his heart as a result of his experience. The lesson he learns is the Malthusian-Darwinian lesson Saki wants to teach the reader.

We can imagine Gortsby's growing bitterness when he remembers how desperately he searched for that young con man in the dusk in order to hand over a sovereign.

Norman Gortsby is a young city dweller who considers himself something of a philosopher as well as a shrewd judge of human character. He is not a gentleman of leisure. He does not have a university education, although he seems tolerably well educated. He probably works in a London office and is sitting on the bench  because he has gotten off work and doesn't want to go home to his modest apartment where he may eventually cook his own supper. He is feeling "heartsore and disillusioned," either because of disappointment in a love affair or some career reversal; the author does not specify the cause. Gortsby is

. . . not disinclined to take a certain cynical pleasure in observing and labelling his fellow wanderers as they went their ways in the dark stretches between the lamp-lights.

This description suggests that the young man who sits down beside him to tell his intricate hard-luck story is going to have a hard time extracting any money from Gortsby, who is willing to listen but not in a charitable mood. He seems to take a sadistic pleasure in pointing out the flaw in the young stranger's story.

"Of course," said Gortsby slowly, "the weak point of your story is that you can't produce the soap."

It seems unlikely that Gortsby would have helped the other man out even if he had produced the soap. But when Gortsby finds a cake of soap by the bench he feels guilty--not only guilty for rejecting the young stranger's story, but also guilty for feeling so cynical and cold about all of humanity. When he rushes to find the other man and give him the sovereign, he is doing it for himself. He is making a decision to change his attitude about his fellow man and become more generous and more "Christian" in the future. The sovereign he gives the young man is like an offering in church, a symbol of atonement.

Saki has been described as a Tory and staunch conservative. He was not the type of person to observe needy people and reflect that the government ought to do more to help them. What his story "Dusk" is really suggesting is that it is a mistake to feel sorry for other people. This is a dog-eat-dog world in which the strongest survive.

The scene pleased Gortsby and harmonized with his present mood. Dusk, to his mind, was the hour of the defeated. Men and women, who had fought and lost, who hid their fallen fortunes and dead hopes as far as possible from the scrutiny of the curious, came forth in this hour of gloaming...

The phrase "who had fought and lost" is indicative of Saki's view that life is a struggle of all against all. He presents his character Norman Gortsby as a sucker for feeling remorse, guilt and shame. Gortsby is not to blame for others' misfortunes, nor is he responsible for helping them out. If the situation had been reversed, if Gortsby had asked the young stranger for the loan of a sovereign--would he have gotten it?

Gortsby has learned a good lesson, according to his creator Saki. When Gortsby sees the elderly gentleman searching for the cake of soap which he just gave to the young con man, along with a sovereign, he realizes that he has been a sucker. In fact, he probably realizes that the elderly gentleman may be a con man himself--and a better con man than the young stranger because he has had the foresight to procure a cake of soap and left it by the bench intentionally, with a plan to come back and use it as an excuse to open a conversation with Gortsby, who in the meantime has left in search of the other con man.

Norman Gortsby is what Americans today would call a yuppie. He is sitting on a park bench and appears to be a man of leisure, but since it is already around six-thirty, he may have gotten off work in some office within the last hour or so. He is fairly well dressed because he would have to be properly attired in conservative clothes in his job. He is not an aristocrat, by any means. He is not an Oxford or Cambridge man, but he has some education and he has an upwardly mobile job, possibly in stocks and bonds. The type of work he does calls for dealing with people, making judgments and decisions, and no doubt with denying many requests. He is not affluent, but he has a better-than-average income and good expectations for the future.

Money troubles did not press on him; had he so wished he could have strolled into the thoroughfares of light and noise, and taken his place among the jostling ranks of those who enjoyed prosperity or struggled for it.

Because he is fairly well dressed and appears to enjoy lounging on park benches watching the passing parade, he has been approached innumerable times by people with hard-luck stories. He has become a bit cynical because he has been taken in by liars before. He is self-reliant; he is not afraid to be sitting there alone in the gathering dusk. He feels confident he can take care of himself in any situation.

When the young man comes and sits beside him, Gortsby probably anticipates some sort of opening conversation and then a request for money. It would seem from his manner and his dialogue that he is willing to amuse himself by listening to the stranger's tale of woe but has no intention of giving him a penny. He automatically assumes that anything the young man will tell him will be untrue. Gortsby has become a connoisseur of hard-luck stories; he has heard them all, both the male and female versions of distress.

Dusk, to his mind, was the hour of the defeated. Men and women, who had fought and lost, who hid their fallen fortunes and dead hopes as far as possible from the scrutiny of the curious, came forth in this hour of gloaming, when their shabby clothes and bowed shoulders and unhappy eyes might pass unnoticed, or, at any rate, unrecognized.

Gortsby is well aware that there are plenty of people in the visinity in financial distress, but he is

. . . not disinclined to take a certain cynical pleasure in observing and labelling his fellow wanderers as they went their ways in the dark sretches between the lamp-lights.

If he tried to help out everybody who appealed to him for money, he would become one of the poor himself. Like Saki himself, Gortsby is a Tory. He knows it is a cold, cruel world and a Darwinian struggle of all against all. He shows his cynicism and his hardened attitude when the young stranger beside him finally finishes his complicated story and prompts him for some sort of response with the words

"I'm glad, anyhow, that you don't think the story outrageously impossible."

"Of course," said Gortsby slowly, "the weak point in your story is that you can't produce the soap."

This slow, thoughtful reponse shows that Gortsby is intelligent, urbane, experienced, judgmental, and cynical. The young stranger's angry reaction suggests that he is sorry to have wasted so much of this valuable twilight time on such an adamant prospect. Gortsby has at least taught him a good lesson. He will buy a cake of soap at the nearest chemist's shop.

Norman Gortsby is young, fairly sophisticated, apparently fairly affluent and well-dressed. The source of his income is not specified. He may be a member of the leisure class, a more numerous class in Saki's day. Gortsby is a great observer of humanity and something of a philosopher. He thinks he is more clever than he actually is. He might be said to resemble Bertie Wooster in the highly popular "Jeeves" stories of P. G. Wodehouse.

Gortsby is a bit cynical but also basically kind-hearted and generous. He ends up giving a complete stranger a soverign to help him out of his trouble. A sovereign, a coin worth one pound, which would have been equivalent to a little over five American dollars at the time of the story--but five American dollars would have been equivalent to at least fifty dollars in buying power today. With a guinea the young man who receives the coin could rent a room for the night in London. An equivalent room in London today would cost at least a hundred pounds.

Gortsby's prosperous appearance and body language are an attraction to a con artist. Gortsby is lounging on a park bench watching the passing parade. It would obviously be easy to start a conversation with him. Park benches seem to invite such approaches. Anyone who sits on a park bench in a big American city today is almost certain to find a friendly stranger sitting beside him who will fairly quickly ask for a dollar or two after striking up a conversation.

Gortsby has probably often killed time lounging on public benches over the years with his hands in his pockets and his legs stretched out in front of him. Consequently, he has undoubtedly been approached by many strangers who have told him many sob stories. He enjoys listening to their stories because he is interested in humanity, and he has probably parted with a lot of coins.

The conclusion of the story is intentionally puzzling. Who is the con artist? Is it the young man who gets the guinea or the elderly gentleman who left the soap by the park bench, either accidentally or on purpose? The elderly gentleman who was sitting beside Gortsby first may have been planning to tell him exactly the same story about having lost his hotel and his soap; but being older and more experienced at the con game, the elderly gentleman may have deliberately left the soap as an excuse to come back and start a conversation, as well as to provide verification for his story. There is no doubt that it is his soap. But what about the other man? He claims he too lost a cake of soap. Gortsby will only know which is the con man if the elderly gentleman begins to tell him the same story about having lost his hotel when he came out to buy a cake of soap--but the story ends before that.

Is there any chance that the young man who borrowed the guinea will actually mail it back to Gortsby as promised? Not likely!

Norman Gortsby is sitting on a park bench at the time between sunset and nightfall. It is getting dark. According to Gortsby, dusk is the hour of defeat. Truly, the defeat of man is evident at dusk, the time of day that characters of less integrity emerge.

While sitting on the bench, the first man that sits next to Gortsby seems dejected and reluctant to go home. Gortsby assumes he gets no respect at home. Of course, this is Gortsby's perception. Gortsby is cynical. He is nontrusting.

When the second man sits down on the bench and has forgotton the name of his hotel and has no money with him, Gortsby is skeptical. The man claims to have gone out to buy a bar of soap. When he cannot produce the bar of soap, Gortsby assumes he is a con artist trying to get money.

Gortsby is definitely skeptical and cynical until the man walks away.Then Gortsby happens to see a bar of soap under the bench. Now, he feels embarrassed for assuming the wrong thing about the second man. He chases after him and gives the con artist money, money that the second man promises to repay.

When the first man comes back looking for his lost bar of soap, Gortsby realizes he has been duped. Again, he is cynical and realizes he will never see his money again.

Dusk is the hour of defeat. Gortsby decided that those who had lost fortunes or had encountered disappointments came out at dusk, thus no one would recognize them or their shabby attire. Of course, Gortsby's trouble is not related to finances, but he is in disillusionment:

He had failed in a more subtle ambition, and for the moment he was heartsore and disillusioned, and not disinclined to take a certain cynical pleasure in observing and labelling his fellow wanderers as they went their ways in the dark stretches between the lamp-lights.

Clearly, Gortsby takes pleasure in his cynicism, and he is not entirely wrong for being cynical for the second man was definitely of lesser character.

In the short story "Dusk," Norman Gortsby is observing people at dusk. Gortsby is a cynical observer. He believes the defeat of man is evident at dusk. He is judgmental of those who sit, or share, the park bench in which he is sitting.

As people are scurrying about, one man joins Gortsby on the bench. From Gortsby's observations, the reader learns that this man seems dejected and reluctant to go home. Gortsby assumes that the man receives no respect at home. Gortsby's assumption indicates that he is cynical and skeptical. He really has no foundation for his assumption about the first man that sits down.

The second man to sit down is truly a con artist. Ironically, this is the man that Gortsby actually or ultimately trusts. Although this second man gives every reason for Gortsby to be cynical or skeptical, in the end, Gortsby decides the second man is trustworthy based on the coincidence of finding a lost bar of soap. Gortsby gives the con artist money, money he will never see again.

Finally learning the truth, Gortsby is justified in his cynicism. It does appear that dusk is a time for the defeat in man to show up. Sadly, it is too late to get his money back.

We aren't actually given that much tangible information regarding this character in "Dusk" by Saki. It is clear however that he is not in want of money and that he could participate in the world of those who are successful. However, for whatever reason, he chooses to dwell in the realm of dusk, which he sees as symbolic of human failure and defeat. Note what we are told about his own defeat as a character:

He had failed in a more subtle ambition, and for the moment he was heartsore and disillusioned, and not disinclined to take a cynical pleasure in observing an dlabelling his fellow wanderers as they went their ways in the dark stretches between the lamp-lights.

Thus we see that Norman Gortsby is a man who is rather pessimistic and cynical, having suffered his own unspecified failure. Likewise, he shows himself to be rather suspicious and quick-thinking in the way that he draws attention to the one piece of evidence that would make him believe the story of the young man. He is likewise humble enough to admit when he has made a mistake and to learn from it, saying that he will not be so quick to judge in future, even though it transpires that the young man was actually lying and by a curious twist of events had successfully duped Gortsby.

A rather supercilious man, Norman Gortsby, sits on a bench in Hyde Part amidst "the defeated" and yet does not consider himself the same since he is without money problems.  His failure, one "in a more subtle ambition," is perhaps in the area of love.  In his disillusionment, he cynically amuses himself with passing judgments on people who traverse the park.  And, he feels confidence in these judgments.  For instance, Gortsby perceives an elderly gentleman next to him as one who has never commanded respect in his life.  Now he is probably isolated either by being ignored in a home or by himself in a lodging. 

As soon as this old gentleman leaves, a young man seats himself in a flurry next to Gortsby, who obligingly takes notice. Of course, while the young man speaks of his misfortunes, the cynical Gortsby gives him no credence.  He tells the young man of the flaw in his story,"...the weak point of your story is that you can't produce the soap," a detail which he says was a convincing one. But, in his smugness, he is defeated by Chance which puts the soap on the ground near the park bench.  Discovering it after the man has departed, and believing it to be the young man's, Gortsby chides himself for being presumptuous and runs after the young man.  With apologies for his disbelief, Gortsby hands the young man the soap.

After he returns to the bench, Gortsby sees the elderly gentleman searching around the bench for his lost soap.  Gortsby is defeated a second time in an illusion. Now, he truly belongs on the bench in the twilight.